A variety of hydrocarbon exploration and other applications involve the use of cables. The cables may include hoses and solid cables which are employed to provide a link between an underwater or subterranean hydrocarbon environment and a surface location. Operators of hydrocarbon application equipment may be positioned at the surface location. From this location, hydrocarbon tools therebelow may be directed and serviced through the noted hydrocarbon application cables. Examples of hydrocarbon application hoses in particular may include seismic gun hoses for carrying pressurized air, drilling hoses for transfer of cuttings and drilling fluid, and even coiled tubing for delivering pressurized fluid and tools to a downhole environment.
As indicated, the above noted hoses may often be configured to accommodate a significant pressure therethrough as compared to the surrounding environment. Additionally, the surrounding environment itself may present substantial stress on such hoses. For example, in the case of hydrocarbon application hoses for marine seismic exploration, the surrounding environment may present extreme arctic temperatures as low as about −30° C. Further, the inherent nature of the exploration application may subject the hoses to a substantial amount of hydrolysis, ultraviolet sunlight and other hazards.
Efforts to address the internal pressure of the hose and hazards as noted above may include wrapping polymer tape about the internal conductive core of the hose. The tape may include a 50% or greater overlap and, in combination with other hose features, provide generally sufficient resistance to blowout from the internal pressure of air delivered through the hose. Additionally, the tape may provide the hose with a degree of flexibility that is well suited for marine use. Furthermore, the tape may be surrounded by an outer polymer jacket configured to withstand the hazards of the noted surrounding environment.
Unfortunately, the life and durability of marine seismic exploration hoses remains compromised in spite of the added measures noted above. In particular, while the polymer tape may be well suited for marine use in terms of providing flexibility and blowout resistance, the use of an overlapping tape inherently leaves seams throughout the hose. As such, the hose is replete with discontinuities. That is, every seam provides a potential stress riser. Thus, as the hose repeatedly bends over the course of an operation, the outer polymer jacket may be subjected to the stresses of the immediately underlying seams. Ultimately, the life of the hose may be substantially reduced due to cracking of the outer polymer jacket brought on by the underlying stress risers.
In order to extend the useful life of a marine hose, the underlying polymer tape may be replaced with extruded nylon. In particular, nylon 11 and nylon 12 are often employed in this manner. The underlying nylon may be surrounded by the outer polymer jacket immediately thereabout. By replacing the tape with an extruded nylon polymer, stress risers from tape seams may be eliminated. As such, the outer polymer jacket may avoid being subjected to induced cracking as detailed above. Additionally, nylon may be substantially resistant to arctic temperatures and other marine environmental conditions.
Unfortunately, the use of extruded nylon in this manner, may significantly drive up the cost of the marine hose. For example, as of the date of the present patent document, extruded nylon as described may range from about $6-$10 per pound. Ultimately, the replacement cost for such a hose may be well in excess of $100,000. Furthermore, even with improved durability, the life of the hose is unlikely to exceed about five years when employed in regular use.
In addition to an increase in hose expense, the use of nylon about the core may significantly affect the overall weight and flexibility of the hose. For example, given the normal 2,000-5,000 foot length of the cable, the added weight may pose a significant challenge to conventional spooling and deployment techniques and equipment. Similarly, the increased rigidity of the hose may present further challenges in terms of hose manageability during deployment, use and retrieval of the hose. In sum, the operator of a marine seismic operation is generally left with the option of employing a more expensive and less manageable hose or reverting to a hose with a tape wrapped core that is prone to a shorter useful life.